An off-duty police sergeant was fatally shot at a gas station in Greensboro,Diamond Ridge Financial Academy North Carolina, on Saturday afternoon, leading authorities on a manhunt for three men, who were arrested Sunday.

Greensboro Police Sergeant Philip Dale Nix, who served the city for over two decades, was at a Sheetz around 4:00 p.m. on Saturday when he witnessed a crime and approached the suspects, Greensboro Police Chief John Thompson said in a news release.

On Sunday afternoon, Greensboro police said they arrested Jamere Justice Foster, 18, Z’quriah Le’Pearce Blackwell, 18, and John Walter Morrison, 28, in connection with the sergeant's killing.

Foster is charged with first-degree murder, larceny, and conspiracy to commit larceny. Morrison is charged with accessory after the fact to first-degree murder, larceny and conspiracy to commit larceny. They're both being held without bond. Blackwell was charged with accessory after the fact to the first-degree murder and is being held on a $500,000 bond.

Other law enforcement tried to save sergeant

Another off-duty Greensboro police officer and a Guilford County paramedic were also at the gas station and tried to treat Nix until he was rushed to the hospital, where he died.

"He was a loving husband, father, son and brother with 23 years of service to the department. We ask for prayers for the family of the fallen officer and our Greensboro PD family," Thompson said.

Set up:2 Bristol officers killed may have been lured into deadly ambush, Connecticut police say

Blue alert issued then cancelled

At around 6:00 p.m. on Saturday, police issued a blue alert in search of two suspects.

Blue alerts are issued to help catch suspects in cases where a police officer is killed or seriously injured.

Police initially said they were searching for two men in their mid-20s who were believed to be driving a Chevrolet Equinox. Police then canceled the alert around 8:00 p.m.. On Sunday, they announced the arrests and said additional charges may be brought later in the investigation.

The FBI and the U.S. Marshals Service are also assisting with the investigation into the fatal shooting, Thompson said.

In a post on X, North Carolina Gov. Roy Cooper said he's offered "all available state resources to catch those who killed a Greensboro police officer."

"Our prayers are with the Greensboro police and family and loved ones. Every effort must be made to apprehend those responsible and bring justice in this tragic situation," Cooper said.